A display screen is one of the most common input and output devices on electronic equipment. A display screen has a capability of displaying text information, image information and video information.
At present, a display screen is usually a wide-viewing-angle display screen, and a viewing angle approximately ranges from 120° to 170°. When a user uses electronic equipment in a crowded place such as on a bus and a metro, others around the user can easily view contents on a display screen, thereby causing leakage of privacy of the user.